The present invention relates to an entrainment separator. More particularly, it relates to an entrainment separator for the separation of entrained solids or liquids from gases, preferably entrained liquids. It also relates to a contactor-separator whereby a mist or drops of a liquid can be contacted with the gaseous stream to further remove entrained liquids, solids and/or soluble or reactive components of the gaseous stream (e.g. SO.sub.2 removal by a caustic wash.)
It has been well known that dispersions of liquids in gases and gases in liquids are always fundamentally unstable mixtures. Left to themselves, they will generally separate into massive collections of the component phases. In many instances, however, such natural separation occurs over a long period of time. For industrial uses and independent of origin of the dispersion, whether intentional or inadvertent, the gas-liquid dispersions generally are always ultimately separated. The separation may consist merely of removal of the aggregated and collected phases, or it may involve aggregation and collection as well as removal. Often the rate at which the process of separation would occur naturally is slow and uneconomical. In such cases the separation operation may be enhanced by the artificial acceleration of the natural process.
There are many reasons why gas-liquid dispersions should be separated. The quality of a process stream or of a product can suffer unless adulterating material in the form of another dispersed phase is removed. The efficiency of staged mass transfer operations can be reduced if there is mechanical carryover of a dispersed phase with the continuous stream from one stage to the next. Valuable material can be lost from a system because of incomplete separation of dispersed material. With improper separation of the gas-liquid dispersion, there can be intrusion of an unwanted phase into equipment along the line of processing which may result in poor performance or damage to the equipment. A discharge of a gas-liquid dispersion from a stack can result in atmospheric pollution and possible destruction of property.
Many methods are employed to separate gas-liquid dispersion systems. Such methods include: gravitational, inertial, absorption, dilution, physiochemical, electrical, and thermal. Often more than one method is effective and the methods may be combined for synergistic effect. Many separators employing the above systems and procedures are the product of invention or accumulated experience and have never been completely described scientifically. Many such methods and apparatus for separating entrained liquids from gases are designed specifically for the conditions peculiar to a given gas-liquid dispersion system and the mechanical apparatus also peculiar to that system.